What is LID?
One of the most important LID principle is the idea that stormwater is not merely a waste product to be disposed of, but rather that rainwater is a resource. LID protects the natural ability of the site to capture precipitation, keep it clean and allow it to recharge the local water table. Often LID techniques:
- Require less constructed infrastructure
- Increase the value of properties
- Preserves valuable site features like trees.
The LID approach is different from conventional development which often clears trees along with valuable topsoil from a site and re-grades it so that all water ends up in a large detention basin. This can cause problems including:
- Loss of recharge
- Increased water temperature
- Decreased water quality
- Higher run-off volumes
LID can save money over conventional approaches through reduced infrastructure and site preparation work including reductions in clearing, grading, pipes, ponds, inlets, curbs, and paving. In addition, long term maintenance costs involve landscaping which is less expensive than infrastructure repair.
Where should LID be used?
LID can be applied to new development, urban retrofits, and redevelopment / revitalization projects at many scales.
At a small scale, LID techniques can be used to better handle rainfall for a single family lot through rain barrels and rain gardens.
At a larger scale, proper site design in combination with many landscaping and infiltration techniques distributed throughout a subdivision can improve rainfall and stormwater run-off management.
Even in the coldest months, LID techniques still encourage retention and, ultimately, infiltration.
The Smart Growth / Smart Energy Toolkit has a number of case studies that you can examine.